That's twice that you have mentioned a lawsuit. What grounds does she have? She was offered the chance to decide the result on the track, and chose to withdraw.

Now, if the coaches were to decide not to have her run in either the preliminary or the final of the 4x100, so she wouldn't win a medal, then maybe she can come up with a case. Note that there is nothing in the rules that says that anybody is "guaranteed" a spot in either round of the 4x100 relay. Being in fourth place in the 100 just guarantees you a spot on the Olympic team.